The present invention relates to a self-contained reaction vessel containing two reactants separated by a frangible seal. Applying pressure to the reaction vessel ruptures the frangible seal and the reactants mix and react to produce a desired reactive effect, such as heating or cooling. The reaction vessels can be used in combination with packages for containing pre-moistened towels, wipes, and other articles.
Hot and cold packs known in the art use two reactants separated by a breakable material that, when broken prior to use, causes the mixing and, thereby, the chemical reacting of the reactants. The resulting reaction can be exothermic or endothermic, and the hot or cold packs can be applied to a localized region on a person""s body. U.S. Pat. No. 3,804,077, issued to Williams, and U.S. Pat. No. 4,067,313, issued to Donnelly teach several embodiments of hot or cold packs. The hot or cold packs can be used to treat injuries, warm hands or feet, or be placed next to food items to retain or achieve desired temperatures.
U.S. Pat. No. 6,289,889, issued to Bell et al., teaches using a flexible heating element having two chambers containing two reactants separated by a frangible seal in combination with a product pouch. Rupturing the frangible seal causes an exothermic reaction which heats the product pouch. The product pouch can contain various materials including liquids, solids, or powders. The product pouch can be porous and contain coffee or tea leaves for simultaneously steeping and heating coffee and tea.
Although a number of self-heating and self-cooling hot and cold packs are known and used in various ways, the basic principles of separating two reactants in separate compartments by a breakable material or seal prior to use can be expanded to include new reactants that provide additional reactive effects in addition to heating and cooling. In addition there is a need for improved packaging for more efficiently using the principles of the two chamber chemical reactant vessel, whether for heating, cooling, or otherwise.
The present invention relates to reaction vessels and the use of the reaction vessels with products and product packaging. The invention provides a reaction vessel including at least two reactant chambers. The reactant chambers are constructed at least in part of a flexible material. A first reactant chamber contains a first reactant and a second reactant chamber contains a second reactant. The first and second reactant chambers are adjacent to each other and separated by a frangible seal. The frangible seal separates the first and second reactant chambers thereby isolating the first and second reactants. Prior to use, pressure is applied to the flexible material of one of the first and second reactant chambers to open or rupture the frangible seal. The opening of the frangible seal allows the mixing of the first and second reactants. The first and second reactants chemically react upon contact. The reaction produces a desired reactive effect on an environment surrounding the reaction vessel and any articles in that environment.
The reaction can be exothermic or endothermic. An exothermic reaction would produce heat that would cause the reactive effect of heating a surrounding environment or article. Oppositely, an endothermic reaction would adsorb energy from the surrounding environment, thereby causing a cooling reactive effect. The reaction vessel can include a conductive material such as a metal foil as a backing material to provide a more efficient energy transfer. xe2x80x9cConductive materialxe2x80x9d refers to a material that is thermally conductive, or in other words, conducts thermal energy or heat. By using an insulating material on a side of the reaction vessel opposite the conductive material, efficiency can again be improved, and the heating or cooling effect can be maximized in a direction towards an article compartment in combination with the reaction vessel.
The reaction vessels of this invention can include reactants that produce additional reaction byproducts or reactive effects. The reactants can react to produce a gas such as oxygen or carbon dioxide, or react by foaming. The reactant chambers can include additional compositions that are activated or otherwise improved through foaming of the reactants. Examples of such foamable compositions include foaming skin washes and foaming disinfectants. The reaction vessel can include a gas-permeable membrane to allow the produced gas to escape the reaction vessel. The gas can be used for reactive effects such as carbonating a beverage or to foam a material in an article compartment in combination with the reaction vessel. If the reactants produce a foaming reaction, the reaction vessel can include an access means such as a tear notch for removing the foamed material, or a porous material that allows the foamed material to exit the reaction vessel.
This invention also relates to packaging for effectively and efficiently using the reaction vessel and the reactive effects produced by the reaction vessel. In one embodiment of this invention, a package for containing an article, such as a pre-moistened towel, includes an article compartment. The article compartment has a first side and a second side opposite the first side. The first side includes a removable portion for access to the article compartment for removing the article therein. The package includes a reaction vessel in combination with the second side of the article compartment. The reaction vessel can be any reaction vessel of the invention producing any of the reactive effects. The reaction vessel includes a first reactant chamber containing a first reactant and a second reactant chamber containing a second reactant. A frangible seal separates the first and second reactant chambers and isolates the reactants until just prior to use.
At least one of the first and second reactant chambers includes a flexible material. Pressure applied to the flexible material of one of the reactant chambers opens the frangible seal and causes the first and second reactants to mix and react. The reaction causes a reactive effect in the article compartment and thereby on the article contained therein. When the reactive effect is a temperature change produced by an exothermic or endothermic reaction, the second side of the article compartment can include a conductive material. When the reactants produce a gas, the second side can include a gas-permeable membrane. Gas-permeable membranes serve to release an evolved gas of the reaction, or may let atmospheric oxygen into the system as a reactant in an oxidation reaction. The gas can enter the article compartment and foam a material contained in the article compartment. The foamed material in turn is picked up by the article for use. Reactants can be chosen that produce a combination of reactive effects such as heating or cooling and producing a gas or foam.
Reactant combinations useful for producing an exothermic reactions are water and calcium chloride or calcium oxide. Water combined with either ammonium, ammonium nitrate, or urea are reactant combinations that produce endothermic reactions. Acid and base combinations, such as citric acid and sodium carbonate or sodium bicarbonate, and acetic acid and sodium bicarbonate, can be used to produce a gas in the reaction vessel. Other reactant combinations include oxidizers and reducers, color changing reactants, and disinfectant-generating reactions, such as those which produce chlorine dioxide (ClO2), chlorine, or iodine, to provide in situ disinfection.
In another embodiment of this invention, a package for containing an article, such as a pre-moistened wipe or facial mask, includes an article compartment for containing an article. The article compartment has an article compartment body extending between a first end and a second end opposite the first end. The second end of the first compartment includes a removable portion for access to the article compartment for removing the article therein. The package further includes a reaction vessel in combination with, and desirably surrounding, the article compartment body. The reaction vessel including a first reactant chamber containing a first reactant is separated from a second reactant chamber containing a second reactant by at least one frangible seal. The reaction vessel is made from a flexible material. Pressure applied to the flexible material opens the frangible seals and the first and second reactants mix and react. The reaction can produce numerous reactive effects on the article as disclosed herein.